A combination of cereals rice (R) and wheat (W) was compared in young adults with mixtures of their constituent amino acids, with and without a 50% increase in lysine (from 1.2 to 1.8 g/day). Nitrogen retention (1.29 g) induced by diet RWL which contained cereals and added lysine was greater (P less than 0.01) than that resulting from all other diets which did not differ from each other. Consumption of diet RW caused lower plasma methionine than diet AA; diet RWL reduced lysine, threonine, isoleucine, leucine, methionine and phenylalanine below values for diet AAL; and diet AA caused lower lysine and threonine but higher valine than diet AAL. Thus, increasing the proportion of lysine was beneficial when cereals but not mixtures of their constituent amino acids were consumed. Three isogenic lines of corn have been tested in young adults: a normal hybrid line; opaque-2 in the same background; and sugary-2. opaque-2 in the same background. The opaque-2 increases lysine and tryptophan and decreases leucine; sugary-2 increases amylose at expense of amylopectin and thereby produces a flinty kernel like the normal corn instead of the floury characteristic of opaque-2. BIBLIOGRAPHIC REFERENCES: Clark, H.E., J.T. Stuff, W.H. Moon and L.B. Bailey. Nitrogen retention and plasma amino acids of men who consume isonitrogenous diets containing egg albumen or mixtures of amino acids. Am. J. Clin. Nutr. 28, 316-324. 1975. Clark, H.E., J.M. Howe and W.H. Moon. Meeting protein and amino acid requirements of man. In Protein Nutritional Quality of Foods and Feeds. Pt. I: Assay methods - biological, biochemical and chemical, p. 11-22. 1975. Ed. M. Friedman. M. Dekker, Inc., N.Y.